Preparing to install the aft top skin on the tailcone and discovered that I never finished the F-609 aft bulkhead. Guess that it's time to get back to the basics - form blocks and sheet metal bending.
Although it would be a little easier to just use a full-size drwg, or even to trust the dimensions on a plan dwg, it was apparent that the F-609 needed to be customized for the fit of the aft top skin which was already drilled and clecoed over the F-608 and F-607 bulkheads. Checked the measurements and confirmed this requirement.
Custom fit the form block on the fuselage to get a perfect fit, then made the 2nd block to match. Used some scrap .025 2024 T3 for the alum and bolted it together. Allowed 5/8th" for the flanges and calculated a rivet spacing, along with fluting, and trimmed the alum to allow flanges to be formed. Used the fly-cutter for a couple of 4" lightening holes.
It seems that the F-609 could use a rolled edge for stiffening but the distance available is minimal and decided to leave it flat.
